Cursor-to-OpenCode: Cursor Rules for OpenCode

Use Cursor .cursor/rules in OpenCode. This OpenCode plugin discovers Cursor rule files, validates frontmatter, dynamically injects matching rules into chat context, and provides /cursor-to-opencode diagnostics for loaded, inactive, skipped, and rejected rules.

Features

• Loads Cursor rules from .cursor/rules/**/*.md and .cursor/rules/**/*.mdc.
• Supports alwaysApply, globs, description, manual rule mentions, @file references, optional .cursorrules, and AGENTS.md detection.
• Dynamically injects only the relevant Cursor rules for the current OpenCode session.
• Reports invalid or unsupported Cursor rules with clear diagnostics.
• Provides /cursor-to-opencode and /cursor-to-opencode stats commands.
• Stores stats outside the project by default so your repo does not get noisy changed files.

Keywords

OpenCode plugin, Cursor rules, .cursor/rules, .cursorrules, Cursor-to-OpenCode, AI coding rules, system prompt injection, OpenCode AI, Cursor AI, developer tools.

Install

Add the npm package to opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": ["@0ct0s3c/cursor-to-opencode@latest"]
}

Pin a release if you want reproducible behavior:

{
  "plugin": ["@0ct0s3c/[email protected]"]
}

Test Locally Before Publishing

You do not need to publish to npm to test this plugin on your computer. OpenCode supports local path plugins.

Build the package:

npm install
npm run build

Then add the local package directory to the OpenCode config for the project you want to test:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": [
    "C:/path/to/Cursor-to-OpenCode"
  ]
}

You can also point directly at the built server file:

{
  "plugin": [
    "file:///C:/path/to/Cursor-to-OpenCode/dist/index.js"
  ]
}

Restart OpenCode after changing opencode.json. Create a test rule such as .cursor/rules/test.mdc in the project being tested:

---
alwaysApply: true
---

Reply with "Cursor rule plugin is active" when asked to verify rules.

Then ask OpenCode to verify the rule. To inspect diagnostics, ask it to call the cursor_to_opencode, cursor_to_opencode_status, or cursor_to_opencode_stats tool.

The plugin intercepts /cursor-to-opencode through OpenCode's command.execute.before hook, the same pattern used by plugins like DCP. Restart OpenCode after changing plugin config, then run:

/cursor-to-opencode

Project injection stats are available with:

/cursor-to-opencode stats

Stats are stored outside the project by default under OpenCode's config directory, so /cursor-to-opencode stats does not create changed files in your repo. Set statsPath only if you explicitly want project-local stats.

If your OpenCode build does not dispatch unknown slash commands to plugin hooks, create .opencode/commands/cursor-to-opencode.md in the project where you are testing:

---
description: Show Cursor rules loaded in this OpenCode session
---

Call the `cursor_to_opencode` tool. Show which Cursor rules were loaded, matched, skipped, or rejected for this session. Include validation warnings and rejection reasons.

Alternatively, define /cursor-to-opencode directly in opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": [
    "file:///C:/path/to/Cursor-to-OpenCode/dist/index.js"
  ],
  "command": {
    "cursor-to-opencode": {
      "description": "Show Cursor rules loaded in this OpenCode session",
      "template": "If the first argument is `stats`, call the `cursor_to_opencode_stats` tool. Otherwise call the `cursor_to_opencode` tool. Show Cursor rule diagnostics clearly."
    }
  }
}

With this config, /cursor-to-opencode is an OpenCode custom command even if hook-dispatched unknown commands are disabled. The plugin still provides the underlying tools.

To debug plugin loading, start OpenCode with:

opencode --print-logs --log-level DEBUG

On Windows, log files are normally under %USERPROFILE%\.local\share\opencode\log.

For release-like testing, run:

npm run ci
npm pack

npm pack verifies the exact tarball that would be published. OpenCode's easiest pre-release path is still the local directory or file:///.../dist/index.js plugin config; use the tarball mainly to inspect package contents.

Manual npm Deploy

GitHub Releases are the preferred publish path, but you can deploy from this machine too.

Create a local .env file that is never committed:

NPM_TOKEN=npm_your_fresh_automation_token

Then run:

npm run deploy

The deploy script:

• loads NPM_TOKEN from .env
• validates package.json uses strict x.y.z semver
• fails if that package version already exists on npm
• runs full CI
• writes a temporary npm config outside the repo
• publishes @0ct0s3c/cursor-to-opencode publicly
• deletes the temporary npm config afterward

Supported Cursor Rule Formats

• .cursor/rules/**/*.md
• .cursor/rules/**/*.mdc
• nested .cursor/rules folders
• .cursor/rules/imported/**
• alwaysApply
• description
• globs
• manual @rule mentions
• @file references for diagnostics
• optional legacy .cursorrules
• AGENTS.md detection for status parity

Cursor User Rules and Team Rules are settings/dashboard data, not normal repo files. The plugin reports those as unsupported external surfaces unless a future option provides an explicit import path.

Dynamic Rule Matching

• alwaysApply: true rules are injected every turn.
• globs rules are injected when a tracked active file matches.
• description-only rules use lightweight prompt/file relevance scoring.
• manual-only rules inject only when mentioned.
• invalid rules are rejected with reason-coded diagnostics.

Commands And Tools

The plugin exposes these OpenCode tools:

• cursor_to_opencode
• cursor_to_opencode_status
• cursor_to_opencode_stats

The plugin also intercepts these slash commands directly through command.execute.before:

• /cursor-to-opencode
• /cursor-to-opencode stats

If your OpenCode build does not dispatch unknown slash commands to plugins, add a command file:

---
description: Show Cursor rules loaded in this OpenCode session
---

Call the `cursor_to_opencode` tool and summarize which Cursor rules loaded, matched, skipped, or failed validation.

Save that as .opencode/commands/cursor-to-opencode.md, then run /cursor-to-opencode.

Options

{
  "plugin": [
    ["@0ct0s3c/cursor-to-opencode@latest", {
      "legacyCursorrules": true,
      "strict": false,
      "maxRulesPerTurn": 20,
      "maxRuleBytes": 120000,
      "intelligentMatching": true,
      "statusCommand": true,
      "includeAgentsMd": false,
      "allowExternalRulePaths": false,
      "statsEnabled": true,
      "statsPath": ""
    }]
  ]
}

By default, statsPath: "" stores stats globally per workspace. If you want the old repo-local behavior, set statsPath to .opencode/cursor-to-opencode-stats.json.

Validation

Known Cursor frontmatter fields are alwaysApply, description, and globs.

The validator rejects invalid YAML, invalid known-field types, empty rule bodies, unreadable rules, and unsafe paths. It warns for unknown fields, ignored fields under alwaysApply: true, oversized rules, unresolved @file references, and YAML-array globs in non-strict mode.

Development

npm install
npm run typecheck
npm run test
npm run build
npm run pack:dry

Publish with the release workflow or npm publish --provenance --access public.